Optical fiber connector assembly

ABSTRACT

Optical fiber connector assembly for a fiber optic cable comprising an optical fiber having an end portion terminated with a ferrule and rod members (4). The optical fiber connector assembly comprises: -a ferrule holder (110) configured to hold the end portion of the optical fiber (10), the ferrule (30) and the rod members (4); -a connector (190) having an internal passageway for housing the ferrule holder (110); -a locking member (180) extending lengthwise and having an internal passageway for the end portion of the fiber optic cable (1). There is also disclosed a pre-connectorized fiber optic cable comprising a fiber optic cable and the optical fiber connector assembly mounted upon an end portion of the fiber optic cable.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/501,660, filed on Feb. 3, 2017, based on PCT/EP2014/066920, filedAug. 6, 2014, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an optical fiber connector assembly.The present invention also relates to a pre-connectorized fiber opticcable comprising said optical fiber connector assembly.

Description of the Related Art

The connection of an optical fiber to another optical fiber is generallycarried out by means of an optical connector. Generally, an opticalfiber connector is a mechanical component used to align and jointogether two optical fibers. The optical fibers may be part of a fiberoptic cable or of a device, such as an optical or opto-electronicdevice. A pre-connectorized fiber optic cable is generally a fiber opticcable having an end portion pre-terminated with an optical connector.

EP 2 052 286 discloses a fiber optic connector assembly comprising aconnector sub-assembly and a retention body, both disposed within ahollow plug housing. The retention body includes a first portion that isconfigured to engage and retain an optical cable comprising an opticalfiber and one or more strength members, and a second portion that isconfigured to engage and retain the connector sub-assembly. Theconnector sub-assembly comprises an optical ferrule optically coupled tothe optical fiber. The second portion of the retention body comprises apair of opposed snap hooks that are configured to engage a correspondingpair of opposed recesses of the connector sub-assembly. The fiber opticconnector assembly further comprises an end cap having an insertion end,configured to be inserted snugly into the back end of the hollow plughousing, and a tapering end configured to receive the optical cable.

It is clear from the above that the fiber optic connector assembly of EP2 052 286 has mechanical couplings between the pieces. In particular, afirst coupling is present between the connector sub-assembly and theretention body and a second coupling is present between the hollow plughousing and the end cap. These types of mechanical couplings, however,do not guarantee high mechanical strength of the whole assembly.

The Applicant faced the technical problem of providing an optical fiberconnector assembly with an alternative and improved design, whichenables to increase the mechanical strength of the whole optical fiberconnector assembly and to avoid cable bending in the proximity of theferrule.

SUMMARY OF THE INVENTION

The Applicant found that it is convenient to have an optical fiberconnector assembly comprising a ferrule holder configured to house anoptical fiber terminated with a ferrule and rod members; a connectorhaving an internal passageway for accommodating the ferrule holder; anda locking member extending lengthwise and having an internal passagewayfor the end portion of the fiber optic cable, wherein each element amongthe ferrule holder, the body and the locking member is mechanicallycoupled to both the other two elements.

In a first aspect the present invention thus relates to an optical fiberconnector assembly for a fiber optic cable comprising an optical fiber,having an end portion terminated with a ferrule, and rod members, theoptical fiber connector assembly extending lengthwise along alongitudinal axis and comprising:

-   -   a ferrule holder configured to hold the end portion of the        optical fiber, the ferrule and the rod members;    -   a connector having an internal passageway for housing the        ferrule holder;    -   a locking member extending lengthwise and having an internal        passageway for the end portion of the fiber optic cable,    -   wherein the connector is configured to be mechanically coupled        to the ferrule holder, and    -   wherein the locking member is configured to be mechanically        coupled both to the ferrule holder and to the connector.

The above configuration, wherein each element of the ferrule holder, thebody and the locking member is directly mechanically coupled to theother two elements (that is, without any intermediate mechanicalcoupling) advantageously enables to improve the mechanical strength ofthe optical fiber connector assembly as a whole and, in particular, boththe tensile strength and the torsion strength. In addition, it enablesto obtain a more compact optical fiber connector assembly. Furthermore,the ferrule holder configured to hold the optical fiber end portion, theferrule and the rod members advantageously avoids cable bending in theproximity of the ferrule.

In a second aspect, the present invention relates to a pre-connectorizedfiber optic cable comprising a fiber optic cable and a optical fiberconnector assembly mounted upon an end portion of the fiber optic cable,the fiber optic cable comprising a cable jacket accommodating an opticalfiber, having an end portion terminated with a ferrule, and rod members,the optical fiber connector assembly comprising:

-   -   a ferrule holder holding the end portion of the optical fiber,        the ferrule and the rod members;    -   a connector accommodating the ferrule holder and configured to        mate with a corresponding receptacle;    -   a locking member extending lengthwise and having an internal        passageway accommodating the end portion of the fiber optic        cable,    -   wherein each element among the ferrule holder, the body and the        locking member is mechanically coupled to both the other two        elements.

For the purpose of the present description and of the appended claims,except where otherwise indicated, all numbers expressing amounts,quantities, percentages, and so forth, are to be understood as beingmodified in all instances by the term “about”. Also, all ranges includeany combination of the maximum and minimum points disclosed and includeany intermediate ranges therein, which may or may not be specificallyenumerated herein.

In the present description, the terms “distal”, “proximal”, “forward”,“front”, “back” in relation to an optical fiber connector assembly areused with reference to an end portion of a fiber optic cable upon whichthe optical fiber connector assembly is mounted. In particular, theterms “proximal” and “back” are used with reference to an element of theoptical fiber connector assembly situated near to the end portion of thefiber optic cable, while the terms “distal”, “front” and “forward” areused with reference to an element of the optical fiber connectorassembly situated away from the end portion of the fiber optic cable.

The present invention in at least one of the aforementioned aspects canhave at least one of the following preferred characteristics.

Preferably, the mechanical coupling between the connector and theferrule holder is made by means of a mechanical coupling configured toprevent relative rotation about said longitudinal axis and relativeaxial movement along said longitudinal axis.

Preferably, the mechanical coupling between the locking member and theconnector is made by means of a mechanical coupling configured toprevent relative rotation about said longitudinal axis and relativeaxial movement along said longitudinal axis.

In a preferred embodiment, said mechanical coupling is a snap coupling.

Preferably, the locking member is configured to be mechanically coupledto the ferrule holder by means of a mechanical coupling configured toprevent relative rotation about said longitudinal axis.

Preferably, the ferrule holder comprises a proximal portion comprising aseat for the end portion of the fiber optic cable.

Preferably, the ferrule holder comprises a distal portion comprising asleeve portion configured to hold the end portion of the optical fiber,the ferrule and the rod members.

In a preferred embodiment, the proximal portion of the ferrule holdercomprises two opposite arms forming said seat.

Preferably, the locking member comprises a distal portion configured tomate with said opposite arms so as to provide said mechanical couplingto the proximal portion of the ferrule holder.

Preferably, the distal portion of the locking member comprises tworecesses extending lengthwise, configured to mate with said oppositearms of the ferrule holder.

In a preferred embodiment, the two opposite arms of the proximal portionof the ferrule holder comprise respective coupling members configured toengage corresponding coupling members in a proximal portion of the body,so as to provide said mechanical coupling between the proximal portionof the body and the proximal portion of the ferrule holder.

Preferably, the ferrule holder comprises a medial portion between thesleeve portion and the proximal portion.

Preferably, the two opposite arms forming said seat extend lengthwiseand project backward from the medial portion of the ferrule holder.

Preferably, the medial portion of the ferrule holder provides anabutment surface for the front face of the end portion of the fiberoptic cable.

Preferably, the medial portion of the ferrule holder comprises a hole incommunication with an internal passageway of the sleeve portion forreceiving the end portion of the optical fiber terminated with theferrule.

Preferably, the sleeve portion of the ferrule holder comprises grooveson its lateral external surface, said grooves extending lengthwisebetween proximal and distal ends of the sleeve portion and beingconfigured to house said rod members.

Preferably, the medial portion comprises holes in communication withsaid grooves for receiving said rod members.

Preferably, the optical fiber connector assembly comprises a firstcrimping element configured to be disposed about the ferrule holder togrip the rod members.

Preferably, the optical fiber connector assembly comprises a secondcrimping element adapted to crimp a proximal portion of the lockingmember about the end portion of the fiber optic cable.

Preferably, the proximal portion of the locking member has on itslateral surface at least one aperture and the second crimping element isadapted to crimp the locking member about the end portion of the fiberoptic cable at said at least one aperture.

Preferably, the body of the connector has a distal portion configured tomate with a corresponding receptacle.

Preferably, the distal portion of the body of the connector isconfigured to house the sleeve portion of the ferrule holder.

Preferably, the distal portion of the body is in the shape of a standardplug housing.

Preferably, the distal portion of the body is devoid of lateralapertures.

Preferably, the proximal portion of the body of the connector isconfigured to house the proximal portion of the ferrule holder.

In a preferred embodiment, the body of the connector is monolithic (i.e.made of one piece).

In a preferred embodiment, the ferrule holder is monolithic (i.e. madeof one piece).

Preferably, the sleeve portion of the ferrule holder comprises aninternal passageway extending lengthwise for accommodating the endportion of the optical fiber terminated with the ferrule.

Preferably, the sleeve portion of the ferrule holder comprises a slotextending lengthwise between distal and proximal ends thereof such as toenable insertion of the end portion of the optical fiber within theinternal passageway of the sleeve portion.

Preferably, the ferrule is associated with a spring, the sleeve portionof the ferrule holder defining an internal shoulder for the spring,proximate a distal end of the sleeve portion.

Preferably, the ferrule comprises a flange.

Preferably, the spring is disposed about the ferrule within the sleeveportion, between said internal shoulder of the sleeve portion and saidflange of the ferrule.

Preferably, the flange of the ferrule has an outer diameter greater thanthe outer diameter of the spring so as to stop the travel of the springin the lengthwise direction beyond the flange, towards a distal end ofthe ferrule.

Preferably, the at least one aperture on the lateral surface of theproximal portion of the locking member comprises two opposite apertures(for example, two diametrically opposite apertures extending lengthwise,preferably of rectangular shape).

Preferably, the optical fiber connector assembly further comprises a nutconfigured to be disposed about the body of the connector.

Preferably, the nut is configured to fix the optical fiber connectorassembly to a corresponding receptacle.

Preferably, the body of the connector comprises a shoulder having anouter diameter greater than an inner diameter the nut such that thetravel of the nut in the lengthwise direction towards the distal end ofthe body is limited, while allowing the nut to freely rotate about thelongitudinal axis relative to the body. Preferably, said shoulder issubstantially located in a medial portion of the body of the connector.

Preferably, the inner diameter of the nut is substantially located incorrespondence of a proximal end of the nut.

Preferably, the optical fiber connector assembly further comprises anadditional nut configured to be disposed about the body.

Preferably, the additional nut has a distal end adapted to engage with aproximal end of the nut.

Preferably, the fiber optic cable comprises yarns that are folded backover the cable jacket of the end portion of the fiber optic cable sothat they are disposed between the internal surface of the lockingmember and the external surface of the cable jacket at the end portionof the fiber optic cable.

Preferably, the fiber optic cable comprises a single optical fiber.

Suitably, the end portion of the optical fiber protrudes from the endportion of the fiber optic cable (the cable jacket being removed fromthe end portion of the fiber optic cable during assembling).

Preferably, the connector is configured to house the ferrule holder sothat a distal end of the ferrule is exposed at a distal end face of theconnector.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present invention will be madeapparent by the following detailed description of some exemplaryembodiments thereof, provided merely by way of non-limiting examples,description that will be conducted by making reference to the attacheddrawings, wherein:

FIG. 1 schematically shows an exploded perspective view of an endportion of a pre-connectorized fiber optic cable according to anembodiment of the invention;

FIG. 2 schematically shows a first perspective view of a ferrule holderof the optical fiber connector assembly of the pre-connectorized fiberoptic cable of FIG. 1;

FIG. 3 schematically shows a second perspective view of the ferruleholder of FIG. 2;

FIG. 4 schematically shows a third perspective view of the ferruleholder of FIGS. 2-3 with an end portion of the fiber optic cable,assembled together;

FIG. 5 schematically shows a first perspective view of the connector ofthe optical fiber connector assembly of the pre-connectorized fiberoptic cable of FIG. 1;

FIG. 6 schematically shows a second perspective view of the connector ofFIG. 5;

FIG. 7 schematically shows a first perspective view of the lockingmember of the optical fiber connector assembly of the pre-connectorizedfiber optic cable of FIG. 1;

FIG. 8 schematically shows a second perspective view of the lockingmember of FIG. 7;

FIG. 9 schematically shows a perspective view of an end portion of afiber optic cable assembled with a ferrule holder and a first crimpingelement, together with a connector and a locking member of the opticalfiber connector assembly of the pre-connectorized fiber optic cable ofFIG. 1;

FIG. 10 schematically shows a perspective view of an end portion of afiber optic cable, a connector and a locking member, assembled together,with a second crimping element of the optical fiber connector assemblyof the pre-connectorized fiber optic cable of FIG. 1;

FIG. 11 schematically shows a perspective view of an end portion of afiber optic cable, a connector, a locking member, a second crimpingelement and a nut assembled together, with a shrinking sheath of theoptical fiber connector assembly of the pre-connectorized fiber opticcable of FIG. 1;

FIG. 12 schematically shows a perspective view of an end portion of afiber optic cable, a connector, a locking member, a second crimpingelement, a nut and a shrinking sheath assembled together, with anadditional nut of the optical fiber connector assembly of thepre-connectorized fiber optic cable of FIG. 1;

FIG. 13a schematically shows a perspective view of the pre-connectorizedfiber optic cable of FIG. 1 wherein the optical fiber connector assemblyis assembled and mounted upon the end portion of the fiber optic cable;

FIG. 13b schematically shows a perspective view of an alternativeembodiment of the pre-connectorized fiber optic cable of FIG. 13 a;

FIG. 14 schematically shows a perspective view of a ferrule holder ofthe optical fiber connector assembly of the pre-connectorized fiberoptic cable of FIG. 1, according to a further preferred embodiment ofthe invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the figures, it is shown a pre-connectorized fiberoptic cable extending lengthwise, along a longitudinal axis. Thepre-connectorized fiber optic cable comprises a fiber optic cable 1 andan optical fiber connector assembly 100 according to an embodiment ofthe invention.

The fiber optic cable 1 comprises an outer protective cable jacket 2housing a single optical fiber 10 and strength members. The strengthmembers comprise flexible yarns 3 (like, for example, aramid yarns)and/or rod members 4, for example in the form of metallic rods. For thesake of illustration, the yarns 3 are shown only in FIG. 1 while rodmembers 4 are shown only in FIGS. 4 and 9.

The outer protective cable jacket 2 at the end portion of the fiberoptic cable 1 is removed so that the end portion of the optical fiber 10and the strength members 3, 4 protrude from the end portion of the fiberoptic cable 1.

The optical fiber 10 preferably is a single mode fiber comprising a coreand a cladding (referred as a whole with the reference number 11). In apreferred embodiment, the core and the cladding 11 are made of a glassmaterial (e.g. silica-based), and a refractive index difference betweenthe core and the cladding 11 is obtained by incorporating suitableadditives (dopants) into the glass matrix of core and/or cladding.Generally, the optical fiber 10, outside the cladding, is provided withan external protective coating 12 made of a polymeric material,typically consisting of two layers. Generally, the diameter of theexternal protective coating 12 is of about 250 μm. Moreover, the outerdiameter of the cladding typically is of about 125 μm.

The optical fiber 10 has an end portion terminated with a ferrule 30.

The ferrule 30 generally is a rigid hollow tube used to hold a strippedend of the optical fiber 10 (that is, stripped of its externalprotective coating 12) and has an internal diameter designed to hold thefiber firmly with a maximum packing fraction. The ferrule 30 provides ameans of positioning the optical fiber 10 within the optical fiberconnector assembly 100 by performing the function of a bushing.

As shown, for example, in FIG. 4, the ferrule 30 has a distal end 32 anda proximal end 34. The ferrule 30 defines an internal passageway thatextends lengthwise between the distal end 32 and the proximal end 34 andwithin which the stripped end of the optical fiber 10 is firmly housed.The stripped end of the optical fiber 10 passes though the ferrule 30such that a front face of the optical fiber 10 is substantially flushwith the distal end 32 of the ferrule 30 or extends somewhat beyond thedistal end 32.

The ferrule 30 comprises a proximal tubular portion 35 (preferablymetallic) and a distal tubular portion 33 (preferably made of glass)separated by a flange 52 (preferably metallic). The ferrule 30 isassociated with a spring 40. The spring 40 is disposed about theproximal tubular portion 35 of the ferrule 30 and urges towards theflange 52. The flange 52 has an outer diameter greater than the outerdiameter of the spring 40 so as to stop the travel of the spring 40 inthe lengthwise direction towards the distal end 32 of the ferrule 30,beyond the flange 52.

The flange 52 preferably comprises a plurality of grooves 51.Preferably, the grooves 51 are equal to each other and equally spaced inthe angular direction, along the circumference of the flange 52.Preferably, the grooves 51 are four, spaced apart of about 90°.

As shown in the example of FIG. 1, the optical fiber connector assembly100 comprises a ferrule holder 110, a connector 190 and a locking member180.

The ferrule holder 110 is preferably monolithic (i.e. made of onepiece).

The ferrule holder 110 is preferably formed of plastic.

As shown in the example of figures from 2 to 4, the ferrule holder 110comprises a sleeve portion 111 (forming a distal portion) and a proximalportion 117.

The sleeve portion 111 extends lengthwise between opposed distal andproximal ends 112, 114 and defines an internal passageway that extendslengthwise between the distal end 112 and the proximal end 114 forhousing the end portion of the optical fiber 10 terminated with theferrule 30.

The sleeve portion 111 provides a support for the assembly ferrule30-spring 40 so that at least the distal portion 33 of the ferrulebeyond the flange 52 projects beyond the sleeve portion 111 (asschematically shown in FIG. 4). Proximate the distal end 112, the sleeve110 defines an internal shoulder 115. The spring 40 is disposed withinthe sleeve portion 111 between the internal shoulder 115 and the flange52.

In a preferred embodiment, the internal passageway of the sleeve portion111 has an inner diameter/size smaller than the outer diameter/size ofthe ferrule 30. This advantageously enables to limit the cross-sectionsize of the sleeve portion 111.

In order to allow the end portion of the optical fiber 10 (which ispre-terminated with the assembly ferrule 30-spring 40) to be insertedwithin the sleeve portion 111, the latter preferably comprises a slot116 extending lengthwise between the distal and proximal ends 112, 114,and having a size such as to enable insertion of the end portion of theoptical fiber 10. Proximate the internal shoulder 115, the slot 116 hasa greater size in the crosswise direction, so as to enable insertion ofthe spring 40 and ferrule 30.

In a preferred embodiment shown in FIG. 14, the sleeve portion 111preferably comprises at least one finger 126 projecting from the distalend 112, providing a support for the assembly ferrule 30-spring 40. Thepresence of more than one finger 126 (in FIG. 14, three fingers 126 areexemplarily shown) enables to improve the firmness of the supportingfunction performed by the sleeve portion 111. Preferably, each finger126 has a distal end with a protrusion 127. Each protrusion 127 ispreferably configured so as to engage one of the grooves 51 of theflange 52. Considering that the front face of the end portion of theoptical fiber 10 can be angled, this enables to orientate the angledfront face of the optical fiber 10 according to a number of positionscorresponding to the number of the grooves 51. As stated above, in theembodiment shown, the grooves 51 are four and equally spaced in theangular direction so that the front face of the optical fiber 10 can beoriented according to four positions angularly spaced apart of 90°. Thisis advantageous because it increases the possibility of matching theangle of the front face of the optical fiber 10 with the angle of amating optical fiber. This advantageously increases the flexibility ofuse of the optical fiber connector assembly 100.

The sleeve portion 111 comprises on the external lateral surface aplurality of grooves 113 that extends lengthwise from the proximal end114 toward the distal end 112 for housing the rod members 4. In theexample, the fiber optic cable 1 comprises two rod members 4 and thesleeve portion 111 comprises two corresponding grooves 113. The grooves113 provide a support for the rod members 4. In the embodiment shown,the grooves 113 are disposed at two diametrically opposite positionswith respect to the slot 116.

The proximal portion 117 of the ferrule holder 110 comprises a seat 118for an end portion of the fiber optic cable 1. The seat 118 has innersize substantially equal to the outer diameter of the protective cablejacket 2 of the fiber optic cable 1.

The seat 118 is configured to receive and mate with the end portion ofthe fiber optic cable 1 (as schematically shown in FIG. 4).

In the embodiment shown (see, in particular, FIGS. 2 and 3), the sleeveportion 111 and the proximal portion 117 of the ferrule holder 110 areseparated by a generally medial portion 119 of the ferrule holder 110.The medial portion 119 is generally disc shaped and disposedsubstantially crosswise, perpendicular to the longitudinal axis of theferrule holder 110.

The medial portion 119 provides an abutment surface for the front faceof the end portion of the fiber optic cable 1. The seat 118 ispreferably defined by a fork configuration of the proximal portion 117of the ferrule holder 110, which comprises two opposed arms 120extending lengthwise and projecting backward from the medial portion119. Except for the walls defined by two opposed arms 120, the rest ofthe seat 118 is open. The two opposed arms 120 are spaced apart by adistance substantially equal to the outer diameter of the protectivecable jacket 2 of the fiber optic cable 1.

The two opposed arms 120 comprise each a snap coupling member 121.

The medial portion 119 of the ferrule holder 110 comprises asubstantially central hole 122. The central hole 122 is in communicationwith the internal passageway of the sleeve portion 111. The central hole122 provides a passage for the end portion of the optical fiber 10. Themedial portion 119 has a slot 123 in communication with the central hole122 and with the slot 116 of the sleeve portion 111. The slot 123 of themedial portion 119 has a size such as to enable insertion of the endportion of the optical fiber 10 into the central hole 122. Preferably,the slot 123 is on an angle (as shown in FIGS. 2-4) so as to prevent theoptical fiber 10 coming out easily once inserted.

The medial portion 119 of the ferrule holder 110 further comprises aplurality of external holes 124. The external holes 124 are incommunication with the grooves 113 of the sleeve portion 111. Theexternal holes 124 are configured to receive the rod members 4 of thefiber optic cable 1. In the example, the external holes 124 are two. Inthe embodiment shown, the two external holes 124 are disposed at twodiametrically opposite positions with respect to the central hole 122,along a transversal axis perpendicular to the longitudinal axis of theferrule holder 110.

The optical fiber connector assembly 100 also comprises a first crimpingelement 125 (see FIG. 9) configured to be disposed about the proximalend 114 of the sleeve portion 111 and to grip the rod members 4. Inorder to provide additional grip, the grooves 113 may be ribbed.

The first crimping element 125 preferably is a hollow cylindrical ring.The crimping element 125 can be, for example, metallic.

As shown in particular in FIGS. 5 and 6, the connector 190 comprises abody 191 which defines an internal passageway that extends lengthwisebetween its ends. The internal passageway has open crosswise end facesand is configured so as to be able to directly house the ferrule holder110 so that the distal end 32 of the ferrule 30 is exposed at the distalend face of the connector 190.

Preferably, the body 191 is monolithic.

The body 191 is preferably formed of plastic.

The body 191 comprises a distal portion 193 and a proximal portion 195extending lengthwise, preferably cylindrical.

The distal portion 193 has an outer diameter smaller than the outerdiameter of the proximal portion 195.

The distal portion 193 preferably has a continuous lateral surface(without openings).

The distal portion 193 ends in the shape of a standard ferrule plughousing and the latter is preferably configured to mate with acorresponding fiber optic receptacle (as, for example, a standard SCadaptor).

In a preferred embodiment (shown in FIGS. 1-4, 9), the medial portion119 of the ferrule holder 110 has a flat portion 128 opposite the slot123. Moreover, the body 191 preferably comprises, in its internalsurface, a flat protrusion (not shown), adapted to mate with the flatportion 128 of the ferrule holder 110 so as to prevent relative rotationbetween the ferrule holder 110 and the body 191 about the longitudinalaxis of the body 191, and to enable positioning of the ferrule holder110 within the body 191 according to a predefined direction.

The distal portion 193 preferably comprises, in its outer surface, acircumferential groove 199 wherein a O-ring 200 is mounted. The O-ring200 is preferably formed of rubber. The O-ring 200 is adapted to matewith a corresponding circumferential groove (not shown) of a fiber opticreceptacle so as to perform a sealing function.

The proximal portion 195 of the body 191 has on its lateral surfacefirst snap coupling members 197. The first snap coupling members 197 areconfigured and disposed in the proximal portion 195 so as to engage withthe snap coupling members 121 on the two opposite arms 120 of theferrule holder 110 and to snap couple the proximal portion 195 of thebody 191 with the proximal portion 117 of the ferrule holder 110.

This snap coupling advantageously enables to mechanically couple thebody 191 and the ferrule holder 110 such as to prevent both a relativerotation and a relative movement between them about/along thelongitudinal axis of the optical fiber connector assembly 100. In theembodiment shown, the first snap coupling members 197 are in the form ofa pair of diametrically opposite openings while the snap couplingmembers 121 are in the form of snap hooks.

The proximal portion 195 of the connector 190 further comprises on itslateral surface second snap coupling members 198. The second snapcoupling members 198 are configured and disposed in the proximal portion195 so as to engage with corresponding snap coupling members 181 (seeFIGS. 5-8) on the locking member 180 and to snap couple the proximalportion 195 of the body 191 with the locking member 180.

The snap coupling members 181, 198 advantageously enable to mechanicallycouple the locking member 180 and the body 191 such as to prevent both arelative rotation and a relative movement between them about/along thelongitudinal axis of the optical fiber connector assembly 100.

In the embodiment shown, the second snap coupling members 198 are in theform of a pair of diametrically opposite openings while the snapcoupling members 181 on the locking member 180 are in the form of a pairof diametrically opposite snap hooks. In the embodiment shown, thesecond snap coupling members 198 are 90° displaced with respect to thefirst snap coupling members 197.

The distal portion 193 and the proximal portion 195 of the body 191 arepreferably separated by a shoulder 196. The shoulder 196 has an outerdiameter greater than the outer diameter of the distal portion 193 andthe outer diameter of the proximal portion 195.

As shown in particular in FIGS. 7 and 8, the locking member 180 isdisposed about a longitudinal axis and extends lengthwise between adistal portion 183 and a proximal portion 185.

Preferably, the locking member 180 is monolithic (e.g. made in onepiece).

The locking member 180 is preferably formed of plastic.

The locking member 180 defines an internal passageway that extendslengthwise between its ends. The internal passageway has open crosswiseend faces and is configured to house the end portion of the fiber opticcable 1.

The distal portion 183 and the proximal portion 185 are generallycylindrical.

The proximal portion 185 is preferably tapered inwards.

The distal portion 183 has an inner diameter substantially equal to theinner diameter of the proximal portion 185 and substantially equal tothe outer diameter of the protective cable jacket 2 of the fiber opticcable 1.

The proximal portion 185 has on its lateral surface at least oneaperture. In particular, in the embodiment shown, the proximal portion185 has a pair of diametrically opposite lateral apertures 187 extendinglengthwise throughout the proximal portion 185.

The distal portion 183 of the locking member 180 has said snap couplingmembers 181 adapted to engage the second snap coupling members 198 onthe proximal portion 195 of the body 191.

The parts of the distal portion 183 of the locking member 180 whereinthe snap coupling members 181 are present are preferably in the form ofa tongue, in order to facilitate the snap coupling between the lockingmember 180 and the body 191.

The distal portion 183 of the locking member 180 comprises a pair ofdiametrically opposite recesses 188 extending lengthwise throughout thedistal portion 183, configured to mate with and accommodate the twoopposite arms 120 of the proximal portion 117 of the ferrule holder 110.This advantageously enables to mechanically couple the locking member180 and the ferrule holder 110 such as to prevent a relative rotationbetween them about the longitudinal axis of the optical fiber connectorassembly 100, while enabling relative axial movement.

The distal portion 183 and the proximal portion 185 are preferablyseparated by a shoulder 186. The shoulder 186 has an outer diametergreater than the outer diameter of the distal portion 183 and theproximal portion 185.

The optical fiber connector assembly 100 further comprises a secondcrimping element 130 (see FIG. 10) to fix the proximal portion 185 ofthe locking member 180 to the end portion of the fiber optic cable 1.The second crimping element 130 is adapted to be disposed about theproximal portion 185 at the lateral apertures 187 and to grip the yarns3 (previously folded back over the cable jacket 2, as explained in moredetail below) together with the cable jacket 2. The presence of thelateral apertures 187 advantageously facilitate the crimping function.

The second crimping element 130 preferably is a hollow cylindrical ring.The crimping element 130 can be, for example, metallic.

The optical fiber connector assembly 100 further comprises a nut 140(see, in particular, FIG. 11) which is configured to be disposed aboutthe body 191 and to fix the optical fiber connector assembly 100 to acorresponding fiber optic receptacle (not shown). The nut 140 may havean internal/external thread (respectively shown in FIGS. 13a and 13b )to threadably engage the fiber optic receptacle by mating with acorresponding external/internal thread of a receiving portion of thefiber optic receptacle.

The nut 140 has a proximal portion with an inner diameter lower than theouter diameter of the shoulder 196 of the body 191 and a distal portionwith an inner diameter greater than the outer diameter of the shoulder196 of the body 191. In this way, the nut 140 is disposed in part aboutthe proximal portion 195 of the body 191 and in part (preferably,mainly) about the distal portion 193 of the body 191. The travel of thenut 140 in the lengthwise direction towards the distal portion 193 ofthe connector 190 is limited, while allowing the nut 140 to freelyrotate about the longitudinal axis relative to the body 191.

The nut 140 is preferably formed of plastic.

The optical fiber connector assembly 100 further comprises a shrinkingsheath 150 (see FIGS. 11-13) which is configured to heat shrink aboutthe end portion of the fiber optic cable 1, the locking member 180, thesecond crimping element 130 and the proximal portion 195 of the body191. The shrinking sheath 150 provides additional retention to the cablejacket 2 and seals the back of the fiber connector assembly 100 aroundthe cable jacket 2. Since the shrinking sheath 150 fits tightly aboutthe cable jacket 2, it seals the optical fiber connector assembly 100from the environment and protect against environmental degradation. Theshrinking sheath 150 could be formed, for example, of Polyolefin (POX),Elastomer (PES), Fluoropolymer (FPM), Polyvinylidenefluoride (PVDF) andPolytetrafluorethylene (PTFE).

The optical fiber connector assembly 100 could also comprise anadditional nut 160 (see FIGS. 12-13), for example formed of rubber,adapted to provide further protection to the back of the optical fiberconnector assembly 100 and an additional grip for a user. A distal endof the additional nut 160 is preferably configured to mate with aproximal end of the nut 140, for example by clipping.

In a preferred embodiment (shown in FIG. 1 only), the pre-connectorizedfiber optic cable could also comprise a dust cap 170 to protect theoptical fiber connector assembly 100 when it is not coupled to acorresponding receptacle.

In the embodiment shown, the dust cap 170 comprises a first cap 171 forthe front face of the ferrule 30, a second cap 173 having a proximalportion with a thread adapted to mate with the thread of the nut 140,and a sealing O-ring 172 adapted to mate with corresponding engagementsin the first and second caps 171, 173 so as to perform a sealingfunction. The dust cap 170 preferably also comprises a lanyard 174having to rings at two opposed ends of the lanyard 174. The rings areadapted to engage, on one side, the optical fiber connector assembly 100and, on the other side, the dust cap 170 such that when the dust cap isremoved from the optical fiber connector assembly 100, the dust cap 170remains coupled to it.

During installation, an end portion of the fiber optic cable 1 isprepared for termination. The cable jacket 2 at the end portion isremoved. The yarns 3 are folded back over the cable jacket 2. Theoptical fiber 10 is terminated with the assembly spring 40-ferrule 30.

The additional nut 160, the shrinking sheath 150, the nut 140, thesecond crimping element 130, the locking member 180 and the O-ring 200are slid backwardly along the end portion of the fiber optic cable 1.

The end portion of the optical fiber 10 is inserted within the internalpassageway of the sleeve portion 111 of the ferrule holder 110, throughthe slots 116, 123 and within the central hole 122 of the medial portion119 of the ferrule holder 110. The assembly spring 40-ferrule 30 isaccommodated within the sleeve portion 111 so that the spring 40 islocated between the internal shoulder 115 of the sleeve 110 and theflange 52 so that the ferrule 30 is biased forwardly. The end portion ofthe fiber optic cable 1 is accommodated within the seat 118 with the endfront face in abutment with the medial portion 119 of the ferrule holder110. The rod members 4 are housed in the respective grooves 113 in thesleeve portion 111, passing through the external holes 124 of the medialportion 119 of the ferrule holder 110 (see FIG. 4).

The first crimping element 125 is disposed about the proximal end 114 ofthe sleeve portion 111 and it is crimped to grip the rod members 4 (seeFIG. 9).

The body 191 is then slid backwardly about the ferrule holder 110 andabout the end portion of the fiber optic cable 1 until the ferruleholder 110 is accommodated within the body 191, the front face of thedistal end 32 of the ferrule 30 is exposed through the open front faceof the body 191, and the first snap coupling members 197 on the proximalportion 195 of the body 191 engage the snap coupling members 121 on thetwo opposed arms 120 of the ferrule holder 110.

The O-ring 200 is slid forwardly along the body 191 until it engages thecorresponding circumferential groove 199 on the distal portion 193 ofthe body 191 (see FIGS. 9-10).

The locking member 180 is slid forwardly along the end portion of thefiber optic cable 1 until the recesses 188 accommodate and mate with thetwo opposite arms 120 of the ferrule holder 110 and the snap couplingmembers 181 of the locking member 180 engage the second snap couplingmembers 198 on the proximal portion 195 of the body 191 (see FIGS.9-10).

The second crimping element 130 is then slid forwardly along the lockingmember 180 until it is disposed about the lateral apertures 187. Then itis crimped to grip the yarns 3 (previously folded back over the cablejacket 2) and the cable jacket 2 (FIGS. 10-11).

The nut 140 is slid forwardly along the body 191 until its travel isstopped by the shoulder 196 (FIG. 11).

The shrinking sheath 150 is heat shrunk about the end portion of thefiber optic cable 1, the locking member 180, the second crimping element130 and the proximal portion 195 of the body 191 (FIGS. 11-12).

In order to complete the assembly, the additional nut 160 is slidforwardly along the body 191 until it clips the back portion of the nut140 (FIGS. 12-13).

The assembly is thus completed, as shown in FIG. 13a and in the variantof FIG. 13 b.

The pre-connectorized fiber optic cable, with the optical fiberconnector assembly 100 thus assembled, is ready to be coupled to acorresponding fiber optic receptacle (not shown). The fiber opticreceptacle can comprise, for example, a receptacle body having aninternal passageway extending through opposite ends. The internalpassageway may accommodate, proximate a first end of the opposite ends,a hollow adapter sleeve (e.g. a standard SC adaptor) adapted to directlyreceive the distal portion 193 of the body 191 (e.g. shaped as astandard SC connector). At said first end, the fiber optic receptaclepreferably also comprises an externally/internally threaded portion forengaging the internal/external thread of the nut 140. Proximate theopposite second end, the internal passageway may accommodate a furtherhollow adapter sleeve adapted to receive a connector assembly coupled toa mating optical fiber.

It will be clear from the above description that the optical fiberconnector assembly 100 of the present description can be coupled to theend portion of the fiber optic cable 1 by means of an improvedmechanical coupling. This is achieved thanks to the fact that eachelement among the ferrule holder 110, the body 191 and the lockingmember 180 is directly (without intermediate elements) mechanicallycoupled to both the other two elements. In particular, the body 191 issnap coupled both to the ferrule holder 110 and the locking member 180so as to prevent any relative rotation and movement between themabout/along the longitudinal axis of the connector assembly 100. Inaddition, the ferrule holder 110 and the locking member 180 are coupledwith a mechanical coupling that prevents any relative rotation betweenthem about said longitudinal axis. This advantageously allows toincrease the mechanical strength of the optical fiber connectorassembly, and the compactness thereof. In addition, the ferrule holder,configured so as to hold the end portion of the optical fiber 10, theferrule 30 and the rod members 4, and to mate with the end portion ofthe fiber optic cable 1, advantageously enables to avoid cable bendingin the proximity of the ferrule 30 and to increase firmness of thecoupling.

1-20. (canceled)
 21. An optical fiber connector assembly for a fiberoptic cable comprising an optical fiber, having an end portionterminated with a ferrule, and rod members, the optical fiber connectorassembly extending lengthwise along a longitudinal axis and comprising:a ferrule holder configured to hold the end portion of the opticalfiber, the ferrule and the rod members; a connector having an internalpassageway for housing the ferrule holder; and a locking memberextending lengthwise and having an internal passageway for the endportion of the fiber optic cable; wherein the connector is configured tobe mechanically coupled to the ferrule holder to prevent relativerotation about the longitudinal axis and relative axial movement alongthe longitudinal axis; and wherein the locking member is configured tobe mechanically coupled both to the ferrule holder and to the connector.22. The optical fiber connector assembly according to claim 21, whereinthe mechanical coupling between the locking member and the connector isalso configured to prevent relative rotation about the longitudinal axisand relative axial movement along the longitudinal axis.
 23. The opticalfiber connector assembly according to claim 21, wherein the mechanicalcoupling between the connector and the ferrule holder is a snapcoupling.
 24. The optical fiber connector assembly according to claim22, wherein the mechanical coupling between the locking member and theconnector is a snap coupling.
 25. The optical fiber connector assemblyaccording to claim 21, wherein the ferrule holder comprises: a proximalportion comprising a seat for the end portion of the fiber optic cable;and a distal portion comprising a sleeve portion configured to hold theend portion of the optical fiber, the ferrule and the rod members. 26.The optical fiber connector assembly according to claim 25, wherein theproximal portion of the ferrule holder comprises two opposite armsforming the seat.
 27. The optical fiber connector assembly according toclaim 26 wherein the locking member comprises a distal portionconfigured to mate with the opposite arms so as to provide themechanical coupling to the proximal portion of the ferrule holder. 28.The optical fiber connector assembly according to claim 27, wherein thedistal portion of the locking member comprises two recesses extendinglengthwise, configured to mate with the opposite arms of the ferruleholder.
 29. The optical fiber connector assembly according to claim 26,wherein the two opposite arms of the proximal portion of the ferruleholder comprise respective coupling members configured to engagecorresponding coupling members in a proximal portion of a body of theconnector, so as to provide the mechanical coupling between the proximalportion of the body of the connector and the proximal portion of theferrule holder.
 30. The optical fiber connector assembly according toclaim 26, wherein the ferrule holder comprises a medial portion betweenthe sleeve portion and the proximal portion.
 31. The optical fiberconnector assembly according to claim 30, wherein the two opposite armsforming said seat extend lengthwise and project backward from the medialportion of the ferrule holder.
 32. The optical fiber connector assemblyaccording to claim 30, wherein the medial portion of the ferrule holderprovides an abutment surface for the front face of the end portion ofthe fiber optic cable.
 33. The optical fiber connector assemblyaccording to claim 30, wherein the medial portion of the ferrule holdercomprises a hole in communication with an internal passageway of thesleeve portion for receiving the end portion of the optical fiberterminated with the ferrule.
 34. The optical fiber connector assemblyaccording to claim 25, wherein the sleeve portion of the ferrule holdercomprises grooves on the lateral external surface thereof, the groovesextending lengthwise between proximal and distal ends of the sleeveportion and being configured to house the rod members.
 35. The opticalfiber connector assembly according to claim 34, wherein the medialportion comprises holes in communication with the grooves for receivingthe rod members.
 36. The optical fiber connector assembly according toclaim 21, comprising a first crimping element configured to be disposedabout the ferrule holder to grip the rod members.
 37. The optical fiberconnector assembly according to claim 21, comprising a second crimpingelement adapted to crimp a proximal portion of the locking member aboutthe end portion of the fiber optic cable.
 38. The optical fiberconnector assembly according to claim 37, wherein a proximal portion ofthe locking member has on a lateral surface thereof at least oneaperture and the second crimping element is adapted to crimp the lockingmember about the end portion of the fiber optic cable at the at leastone aperture.
 39. An optical fiber connector assembly for a fiber opticcable comprising an optical fiber, having an end portion terminated witha ferrule, and rod members, the optical fiber connector assemblyextending lengthwise along a longitudinal axis and comprising: a ferruleholder configured to hold the end portion of the optical fiber, theferrule and the rod members, a connector having an internal passagewayfor housing the ferrule holder; and a locking member extendinglengthwise and having an internal passageway for the end portion of thefiber optic cable, wherein the connector is configured to bemechanically coupled to the ferrule holder by a mechanical fastening,and wherein the locking member is configured to be mechanically coupledboth to the ferrule holder and to the connector.
 40. An optical fiberconnector assembly for a fiber optic cable comprising an optical fiber,having an end portion terminated with a ferrule, and rod members, theoptical fiber connector assembly extending lengthwise along alongitudinal axis and comprising: a ferrule holder configured to holdthe end portion of the optical fiber, the ferrule and the rod members, aconnector having an internal passageway for housing the ferrule holder;and a locking member extending lengthwise and having an internalpassageway for the end portion of the fiber optic cable, wherein theconnector is configured to be mechanically coupled to the ferruleholder, and wherein the locking member is configured to be directlymechanically coupled both to the ferrule holder and to the connector toprevent relative rotation between the ferrule holder and the connectorabout the longitudinal axis, while enabling relative axial movement.